The present invention relates to a kit for use with field communication distribution equipment and, more particularly, to an improved cable connector seal kit that includes torque limiting spacers or stand offs.
The J-1077 A/U distribution box (hereinafter referred to simply as the “J-1077”) is used to interconnect military field telephones and other communication devices in mobile, transportable, and semi-permanent installations. The J-1077 has provisions for connection of one or two 26 conductor-pair cables to a set of 26 pairs of spring post connectors mounted on a panel within the box. The standard cable for use with J-1077 type boxes is designated CX-4566 A/G. As such, the J-1077 can interconnect two 26-pair cables or can terminate a single 26-pair cable and provide connections to the conductors within the cable, such as for telephone sets or test equipment. The J-1077 has been in use for several decades and has proved to be generally rugged and reliable in varied field conditions. Additional information about the J-1077 distribution box can be obtained from Associated Industries of North Hollywood, Calif. (www.associated-ind.com) and from other sources.
The J-1077 distribution box and the standard CX-4566 A/G cable were originally designed for carrying multiple channels of audio frequency telephone signals. Military field communications have evolved beyond voice and teletype communications to high speed data communications for text, numeric, and image date in addition to voice signals. United States military services also make use of an expanded field distribution box or signal distribution panel designated as the J-2317 A/U box (referred to hereinafter simply as the J-2317 box) which has the interconnection capabilities of four J-1077 boxes. The conventional J-2317 box includes four 26-pair cable connectors, designated as connectors A, B, C, and D. Each cable connector terminates at a respective set of binding posts to enable patching of communications devices to 26-pair cables connected to the cable connectors.
A number of shortcomings for the J-1077 and J-2317 boxes have been remedied by the communication equipment disclosed in co-owned U.S. Pat. No. 7,238,063, U.S. Pat. No. 7,445,520, U.S. Pat. No. 7,625,248, U.S. Pat. No. 7,625,249, and U.S. Pat. No. 7,628,659; the entire contents of which patents are incorporated herein by reference.
In order to provide for digital communications between computers and computerized equipment, improved J-1077 type distribution boxes may have some of the insulation displacement connectors interconnected to connectors more appropriate for computer networks or for interconnections between modems. Such connectors can include, but are not limited to, RJ-45 (8P8C), RJ-11, and RJ-12 modular type connectors; BNC type connectors; and other connectors commonly employed for interconnections between computers. Conductors of the cables interconnecting the improved J-1077 boxes and carrying data between computers may be shielded separately from the other conductor pairs to minimize possible interference to and from other signals on other conductor pairs. Data connectors and associated cable conductors would provide some limited computer networking capabilities in addition to more conventional analog voice communications in systems employing J-1077 type distribution boxes. Alternatively, other types of connectors can be connected to selected insulation displacement connectors, such as standard phone connectors, F-type connectors, fiber optic adapters, and other standard types of network, telephone, audio, video, and signal connectors. The insulation displacement connectors and the auxiliary connectors are connected to a pair of box connectors positioned on opposite sides of the box to enable the distribution box to be connected to other boxes. The box connectors have sets of contacts which correspond to the conductors of the insulation displacement connectors and the auxiliary connectors.
A preferred type of box connector is designated U-187 A/G which is referred to as a side mount connector in which a side of the box connector structure is joined to the side wall of the box. It is foreseen that the box connector could alternatively be a U-186 C/G connector which is substantially similar to the U-187 A/G except that the U-186 C/G connector is joined to a side wall of the box by an end of the connector structure.
A preferred type of cable includes a plurality of pairs of cable conductors positioned within a conductive shield and an insulative tubular sheath. The cable may also include an outer “armor” layer which reduces damage from being chewed by animals and from other hazards. Each end of the cable includes a cable connector with a plurality of sets of contacts to which the cable conductors are connected. The cable connector is configured to be compatible with the configuration of the box connector. The conductor pairs, in cooperation with the cable connector, are configured to comply with Category 5E (Cat 5E) specifications. Cat 5E conductor pairs are typically twisted at a twist pitch of three twists per inch (2.54 cm). Preferably, the twist is maintained within the cable connector to within one-half inch (12.7 mm) of the contact terminal set to which the conductors are soldered. The conductor pairs and connector may be configured to specifications more stringent than Cat 5E.
Cable connectors with the military designation U-185 B/G and U-187 A/G are used to connect 26-pair Cat 3 and Cat 5E cables with each other and with the J-1077 or J-2317 box. Typically, both ends of the cables will have U-185 B/G connectors which are compatible with both the U-187 A/G and U-186 C/G box connectors. The U-185 B/G connector is a “genderless” type of connector and may be connected to another U-185 B/G connector to thereby connect one cable to another cable. The cable may also be provided at one end with another type of connector, such as a standard type of multi-contact cylindrical connector designated MS-27467 or AE167, often referred to as a barrel or Cannon connector.
The cable connectors are designed to provide a weatherproof encasement for a contact array board assembly having the standard military designation of MX-3227/G. The MX-3227/G includes a circuit board that enables electrical contact through the cable to the field communication box. The MX-3227/G is installed in each of the mating halves of a pair of cable connectors by fasteners that extend inboard from the outside surface of the connector. The connection posts on the inward-facing surfaces of the circuit boards are evenly sized, but the inner surfaces of the cable connector shells are stepped. When properly installed, the board fits flat within the rim of its respective cable connector shell, with one side floating over the stepped down portion of the shell. In the field, technicians install or replace the boards by inserting screw-type fasteners through the outside of the housing and into the connection posts without benefit of any torque specifications. This inevitably results in over tightening of the connector to the board on the floating side of the board, causing a crooked installation. When two misaligned connectors are matingly engaged, this leaves open contacts or connection points and causes the field communication device to malfunction.
The U-185/U-187 connector system was designed and built in the early 1960's to be rugged and reliable. In use, however, the connectors can rarely be fully closed and locked. Field personnel address this issue by forcing the mating parts together, which exerts pressure on the existing gaskets and on the MX-3227/G circuit boards when they are forced together. When the connector cannot be fully closed, the compressed gaskets will force the connectors apart, causing loss of a positive seal, allowing entry of moisture and dirt, and may result in intermittent or continuous interruption of circuit continuity between the cable and the box. This creates a perceived need for active line retorque of the fasteners on the MX-3227/G insert in order force the parts together, which may result in damage to the insert.
Over tightening and failure to achieve full connector closure thus result in misalignment of the MX-3227/G contact array boards and damage from excessive gasket pressure, which result in poor electrical connections between the cable and the box, which negatively affects the performance and reliability of the field data distribution system. Because the U-185 B/G and U-185 A/G cannot be locked in a fully closed position, these connectors are not fully utilized, which results in waste of the substantial cache of cables and equipment that utilize the U-185 B/G and/or U-185 A/G.
Thus there is a need for a cable connection system for 26 pair Cat 5E cables and field communication boxes that enables them to be connected in a fully closed and locked position with the MX-3227/G contacts properly aligned for full contact, and without excessive torque or damage to the MX-3227/G insert. In addition, there is a need for such a cable connection system that would enable the military to utilize its existing cache of cables and equipment that employ the U-185 B/G and/or U-185 A/G connectors.